Antique Art Deco Platinum Three-Stone Ring with 0.43ct Old European Cut Diamond & Baguette Accents, circa 1928–1941

This sophisticated antique ring is a beautiful example of American Art Deco design, dating to approximately 1928–1941. Crafted in platinum and bearing the desirable "10% IRID PLAT." hallmark, it reflects the precision, elegance, and architectural styling that defined fine jewelry during the mature Art Deco period.

At its center sits a 0.43 carat natural Old European Cut diamond, prized for its high crown, smaller table, and broad antique facets that create a soft, romantic brilliance distinct from modern brilliant-cut diamonds. The center stone is framed by approximately 0.12 carats of natural accent diamonds, combining both Old European Cut and baguette-cut diamonds in a classic Art Deco arrangement.

The baguette diamonds introduce the clean, linear geometry that became synonymous with the Art Deco movement, while the round Old European Cut diamonds provide contrast with their softer antique faceting. Together, they create a balanced composition that highlights both sparkle and architectural form.

The center diamond is held in a finely crafted open prong setting that allows light to enter from multiple angles. The shoulders feature carefully arranged round and baguette diamonds that taper gracefully into a slender platinum shank, giving the ring an elegant profile while maintaining everyday wearability.

Crafted in platinum, the mounting exhibits the crisp detail and delicate metalwork that made platinum the preferred precious metal of high-quality Art Deco jewelry. The ring's understated proportions and timeless design make it equally suited as an antique engagement ring or an heirloom-quality addition to a vintage jewelry collection.

Details

• Era: Art Deco
• Date: Circa 1928–1941
• Metal: Platinum
• Hallmark: 10% IRID PLAT.
• Center Stone: Natural Diamond
• Center Stone Weight: 0.43 ct
• Center Stone Cut: Old European Cut
• Accent Stones: Natural Diamonds
• Accent Diamond Weight: Approximately 0.12 ct total
• Accent Diamond Cuts: Old European Cut & Baguette Cut
• Approximate Total Diamond Weight: 0.55 ct
• Setting Style: Three-Stone with Baguette Accents
• Center Setting: Open prong setting
• Shoulder Design: Round Old European Cut diamonds with baguette diamond accents
• Shank: Tapered platinum shank
• Style: Art Deco, Antique, Engagement Ring
• Condition: Antique / Estate condition with age-appropriate wear

Collector's Note

The "10% IRID PLAT." hallmark is one of the most desirable authentication features found on American platinum jewelry from the Art Deco era. Platinum-iridium alloys were widely used before World War II, making this stamp a strong indicator of pre-1941 manufacture.

The combination of Old European Cut and baguette-cut diamonds is a hallmark of mature Art Deco design, pairing the warm brilliance of antique-cut diamonds with the crisp, geometric lines that defined the period. Together, these elements create a timeless engagement ring that beautifully represents one of the most celebrated eras in jewelry history.

Disclosure: The current 0.43 ct Old European Cut center diamond is a later replacement. While it is period-appropriate and complements the mounting beautifully, it is not believed to be the ring's original center stone. This does not diminish the authenticity of the Art Deco platinum mounting, but it is an important historical detail that needs to be disclosed for complete accuracy.

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